JP2007101462A - Weighing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a weighing apparatus for carrying out high-accuracy weighing by reducing the influence due to the vibration of the floor surface. <P>SOLUTION: A weight checker 1 has: a fixed end 5b of a side connected to the floor face; and a free end 5c connected to a side of conveyors 3ba-3bc mounting a substance X to be weighed on both the ends of a load cell 5 for weighing the substance X to be weighed conveyed on the conveyors 3ba-3bc. The weighing apparatus is in a non-contact state with the fixed end 5b, and provided with a drive motor M2 that is a weight substance, at a position adjacent to the fixed end 5b. The drive motor M2 is connected to the side of the free end 5c, by using arm members 21 and 23 and the like. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a weighing device for weighing an object to be weighed by a built-in weighing sensor such as a load cell.

In recent years, as a weight checker for determining whether or not the weight value of an object to be weighed is within a predetermined range, the object to be weighed is measured on a transport conveyor or a transport conveyor that transports the object to be weighed in a predetermined direction. A weighing device equipped with a weighing sensor or the like is used.
In such a weighing device, generally, a heavy object such as a drive motor for driving the conveyor is arranged close to the weighing sensor, so that the inertial moment in the weighing sensor is reduced and high-precision weighing is performed. It can be performed.

For example, Patent Literature 1 discloses a weighing conveyor (weighing device) in which a drive motor for a conveyor is installed in the vicinity of a load cell (weighing sensor) on the free end side (FIG. 4 of Patent Literature 1). reference).
JP 2001-317986 A (published on November 16, 2001) JP 2002-39845 A (published February 6, 2002) US Pat. No. 4,570,729

However, the conventional weighing device has the following problems.
That is, in the weighing device disclosed in the above publication, a moment of inertia in the weighing sensor is reduced by arranging a heavy object such as a drive motor in the vicinity of the weighing sensor. However, since the vibration of the floor surface is transmitted from below the fixed end, if the distance from the position of contact of the weighing device with the floor surface increases, the weighing sensor becomes susceptible to the vibration on the floor surface. End up.

  Here, in the configuration disclosed in the above publication, since a heavy object such as a drive motor is attached to the free end side opposite to the fixed end when viewed from the weighing sensor, the gravity center position of the weighing device is free. It is formed on the end side. For this reason, the vibration on the floor surface is transmitted from the fixed end side to the weighing sensor, but the drive motor, which is a heavy object, is separated from the contact portion between the floor surface and the device and the center of gravity of the device. There is a possibility that the weighing sensor is easily affected by the vibration of the floor surface and high-precision weighing cannot be performed. And since it is the same also about the vibration in the state in which the to-be-measured object is mounted in the weighing conveyor, weighing accuracy will fall.

  An object of the present invention is to provide a weighing device capable of reducing the influence of vibration on the floor surface and preventing high-frequency measurement while preventing vibration during measurement and reduction in natural frequency. .

  A weighing device according to a first invention includes a weighing sensor for weighing an object to be weighed, a fixed end, a free end, a heavy object, and a connecting portion. The fixed end is an end on the fixed side to which the weighing sensor is attached. The free end is the end of the weighing sensor opposite to the fixed end, and the object to be weighed is placed on the free end. The heavy object is arranged at a position where the fixed end is sandwiched between the weighing sensor and the fixed end in a non-contact state with the fixed end. A connection part connects a free end and a heavy article.

Here, the center of gravity distance of the device is fixed by specifying the positional relationship between the fixed and free ends of weighing sensors such as load cells and force balances that weigh the objects to be weighed and the heavy objects included in the weighing device. We provide a weighing device that can move to the side to reduce the influence of floor vibrations and perform highly accurate weighing.
Here, the above-mentioned heavy items include, for example, a conveyance conveyor that conveys an object to be weighed, a conveyance motor that drives the conveyor, a cylinder that rotates a part of the conveyance conveyor in the vertical direction to distribute the object to be weighed, and weighing Includes hopper, weighing pan, etc.

  As a result, since the free end of the weighing sensor and the heavy object are respectively arranged on both sides with the fixed end of the weighing sensor as the center, the gravity center position of the weighing device is moved to the side where the heavy object is arranged. it can. As a result, when weighing with the object to be weighed placed on the free end side, the center of gravity position of the device is moved from the free end side to the fixed end side in contact with the floor, as compared with the prior art. Therefore, it is possible to perform weighing with higher accuracy than in the past by avoiding that the weighing accuracy in the weighing sensor is lowered due to the influence of vibration on the floor.

A weighing device according to a second invention is the weighing device according to the first invention, and the heavy object is a member that releases heat.
Here, a heavy object arranged so as to sandwich the fixed end together with the weighing sensor is a heat source that releases heat to the outside.
Here, as a heavy object that can be a heat source, for example, a transport motor that drives a transport conveyor that transports an object to be weighed, a cylinder that rotates a part of the transport conveyor in the vertical direction to distribute the object to be weighed, etc. Is included.

  As a result, even when a heavy object serving as a heat source is provided on the fixed end side as viewed from the weighing sensor, the weighing sensor and the heavy object serving as the heat source are not in direct contact with each other. Therefore, it is possible to reduce adverse effects such as heating only a part. As a result, even when a load cell is used as a weighing sensor, the four-corner error and temperature drift in the so-called weighing sensor due to changes in the Young's modulus and electrical resistance of the sensor strain body are avoided and the weighing accuracy is reduced. Can do. Further, even when force balance is used as a weighing sensor, it is possible to avoid a decrease in weighing accuracy due to a large four-corner error in a so-called weighing sensor due to a change in the differential transformer.

A weighing device according to a third aspect of the present invention is the weighing device according to the second aspect of the present invention, and further includes an adjustment mechanism that adjusts the amount of heat released from the heavy article and transmitted to the weighing sensor.
Here, the amount of heat transferred from the heavy object serving as the heat source to the weighing sensor is adjusted by the adjusting mechanism.
Here, the adjustment mechanism is configured such that a part such as a heat insulating material or a heat radiating material provided between a heavy object serving as a heat source and a fixed end on the fixed side or a motor serving as a heat source is away from the fixed end. Etc. are included.
As described above, by providing the adjustment mechanism, it is possible to avoid heat from being transmitted to the weighing sensor via the fixed end, and thus it is possible to avoid a decrease in weighing accuracy in the weighing sensor. .

A metering device according to a fourth invention is the metering device according to the third invention, wherein the fixed end and the connecting portion are made of a material having a high thermal conductivity.
Here, the fixed end to which the weighing sensor is attached and the connecting portion that connects the free end and the heavy object are formed of a material that efficiently transmits heat generated from the heavy object mounted on the apparatus.

Here, examples of the material having high thermal conductivity include an aluminum alloy.
As a result, the heat generated from the heavy object is transmitted to the directly connected connecting portion and the fixed end arranged in close proximity while being in a non-contact state. At this time, since the fixed end to which heat is indirectly transmitted via air is closer in distance than the connecting portion to which heat is directly transmitted, the heat transmitted to the weighing sensor is at both ends of the weighing sensor. It becomes almost equal at (fixed end, free end). As a result, it is possible to prevent a measurement error from increasing due to temperature unevenness as a result of heating a part of the weighing sensor. Furthermore, since the heat transfer at the start-up (power-on) of the apparatus is accelerated, the rise-up (warm-up) time can be shortened.

A metering device according to a fifth invention is the metering device according to the third invention, wherein the fixed end and the connecting portion are made of a material having low thermal conductivity.
Here, the fixed end to which the weighing sensor is attached and the connecting portion that connects the free end and the heavy object are formed of a material that is difficult to transmit heat generated from the heavy object mounted on the apparatus.

Here, as a material with low thermal conductivity, resin etc. are mentioned, for example.
Thereby, the heat generated from the heavy object is difficult to be transmitted to the directly connected connecting portion and the fixed end that is disposed in close proximity to the non-contact state. For this reason, since a fixed end etc. can be functioned as a heat insulation wall, there is almost no heat transmitted to a measuring sensor, and temperature distribution in both ends (fixed end, free end) of a measuring sensor becomes almost equal. As a result, it is possible to prevent a measurement error from increasing due to temperature unevenness as a result of heating a part of the weighing sensor. Furthermore, by arranging the fixed end close to the heat source or expanding the fixed end upward, the amount of heat transmitted to the weighing sensor can be controlled to form a thermally stable state.

A metering device according to a sixth invention is the metering device according to any one of the first to fifth inventions, wherein the fixed end is a flow of air that is generated by the movement of a heavy object and flows toward the metering sensor. It has a wind barrier that blocks the wind.
Here, the fixed end of the weighing sensor also functions as a windbreak wall that blocks the flow of air that is generated by driving a heavy object and flows toward the weighing sensor.

  Thereby, even when a heavy object is accompanied by a movement at the time of driving like a motor or a cylinder, the influence of the air flow caused by the movement of the weighing sensor can be eliminated. As a result, even when a heavy object that generates an air flow at the time of driving is mounted, it is possible to carry out high-precision measurement by eliminating the influence of the air flow without providing a separate component.

A weighing device according to a seventh aspect is the weighing device according to any one of the first to sixth aspects, wherein the heavy object and the weighing sensor are housed in the same casing.
Here, among the constituent members arranged as described above, the heavy object and the weighing sensor are accommodated in the same casing.
Thereby, the measuring apparatus excellent in dustproofness, waterproofness, or cleanability can be provided.

A weighing device according to an eighth aspect of the present invention is the weighing device according to any one of the first to seventh aspects of the present invention, further comprising a conveyor for conveying the object to be weighed in a predetermined direction, A drive motor for driving the conveyor.
Here, a driving motor for driving a conveyor for conveying an object to be weighed provided in a conveyor such as a weight checker is mounted as a heavy object.

  As a result, even when this drive motor functions not only as a heavy object but also as a heat source, it is possible to reduce the influence of vibration from the floor and the influence of heat generated from the drive motor, and carry out highly accurate weighing. A possible metering device can be obtained.

  According to the weighing device of the present invention, it is possible to avoid the deterioration of the weighing accuracy of the weighing sensor due to the influence of vibration and heat on the floor and to perform weighing with higher accuracy than before.

A weight checker (weighing device) 1 according to an embodiment of the present invention will be described below with reference to FIGS.
Regarding the “front-rear” direction used in the following description, the upstream side in the transport direction A shown in FIG. 1 is the “rear” side, and the downstream side is the “front” side.
[Configuration of the entire weight checker 1]
As shown in FIG. 1, the weight checker 1 according to the present embodiment mainly includes a flat belt type conveyor device 3 and a load cell (weighing sensor, first weighing sensor) 5 (see FIG. 3), an AFV (Anti Floor Vibration) (second weighing sensor) 6 (see FIG. 3), which is a load cell for detecting the influence of vibration on the floor surface, a housing 7 for housing the load cell 5 and AFV 6, and a housing A pair of front and rear legs 10 and 11 for fixing the body 7 and a frame (support member) 20 (see FIG. 3) for housing the AFV 6 in the internal space are provided. Further, the weight checker 1 is arranged as the last device constituting the production line, and while being conveyed in the direction of the arrow A in the conveyor device 3, for example, an object to be weighed X supplied from a bag making and packaging machine (not shown). Then, after determining whether it is a non-defective product or a non-defective product, only the object to be weighed X determined to be non-defective is conveyed to a metal detector (not shown) disposed on the downstream side.

  As shown in FIG. 1, the conveyor apparatus 3 is provided with a first transport unit 3a, a second transport unit 3b, and a third transport unit 3c in order from the upstream side in the transport direction A of the object to be weighed X. As shown in FIG. 2, each of the first to third transport units 3a to 3c further includes three conveyors 3aa to 3ac, 3ba to 3bc, and 3ca to 3cc arranged in a direction orthogonal to the transport direction. It is configured to include. In each of the conveyors 3aa to 3cc, an endless conveyance belt as a conveyance belt is wound between a pair of front and rear rollers 13 and 15.

The roller 13 on the downstream side in the transport direction A is a driving roller to which a rotational driving force is transmitted by driving motors M1 and M2 (see FIG. 3) described later. On the other hand, the upstream roller 15 is a driven roller that rotates when the rotational driving force from the roller 13 that is a driving roller is transmitted through the conveying belt.
The first transport unit 3a is disposed on the most upstream side in the transport direction A, and receives an object to be weighed X sent from a bag making and packaging machine (not shown) disposed on the upstream side of the weight checker 1 in the transport direction. It conveys toward A and delivers the to-be-measured object X with respect to the 2nd conveyance part 3b.

The second transport unit 3b is disposed between the first transport unit 3a and the third transport unit 3c, and the weighing is performed using the load cell 5 and the AFV 6 while transporting the object X here. . The weighing of the object X in the second transport unit 3b will be described in detail later.
The 3rd conveyance part 3c is arrange | positioned at the most downstream side in the conveyance direction A, and as shown in FIG. 1, it rotates centering | focusing on the edge part of an upstream side. Thereby, the to-be-measured object X is distributed based on the measurement result in the 2nd conveyance part 3b. Specifically, when the measurement result in the second transport unit 3b is within a predetermined weight range, the third transport unit 3c is set to a substantially horizontal state indicated by a solid line in FIG. It is conveyed downstream as it is. On the other hand, when the measurement result in the second transport unit 3b is out of the predetermined weight range, the third transport unit 3c is rotated to the obliquely downward state shown by the dotted line in FIG. And the object to be weighed X (defective product) is conveyed.

As shown in FIG. 3, the drive motor M1 is provided for each of the three most upstream conveyors 3aa to 3ac, and is disposed below each of the conveyors 3aa to 3ac. The rollers of the conveyors 3aa to 3ac are provided. A rotational driving force is transmitted to 13 through a driving belt.
As shown in FIG. 4, the drive motor (heavy object, heat source) M2 is provided below the three conveyors 3ba to 3bc provided between the most upstream conveyors 3aa to 3ac and the most downstream conveyors 3ca to 3cc. It is arrange | positioned and rotational drive force is transmitted via a drive belt with respect to the roller 13 of each conveyor 3ba-3bc. The drive motor M2 serves as a heat source that releases heat when a rotational driving force is transmitted to the roller 13.

  As shown in FIGS. 1 and 3 and the like, the load cell 5 is disposed in the same casing 7 as the heavy drive motor M2 with the longitudinal direction thereof along the transport direction A. Further, as shown in FIG. 4, the load cell 5 is attached to a fixed end (adjustment mechanism, windbreak wall) 5b so as to be adjacent to the drive motor M2, and an arm member (connected to the free end 5c side) Weighing the object to be weighed X is detected by detecting a change in distortion caused by the object X being placed on the conveyors 3ba to 3bc via the connecting part) 21.

  The fixed end 5b and the free end 5c are located in the front-rear direction of the load cell 5, as shown in FIG. The fixed end 5b is formed of a material such as an aluminum alloy having high rigidity, light weight, and high thermal conductivity, and is connected to the pair of legs 10 and 11 through a plurality of parts (not shown). For this reason, even when the heat released from the drive motor M2 is transmitted to the fixed end 5b, the heat can be released through the legs 10 and 11. The fixed end 5b is arranged between the load cell 5 and the heavy drive motor M2, thereby preventing wind generated during the drive of the drive motor M2 from flowing into the load cell 5. Functions as a wind barrier. On the other hand, like the fixed end 5b, the free end 5c is made of a material such as an aluminum alloy having high rigidity, light weight and high thermal conductivity, and is connected to the conveyors 3ba to 3bc via the arm member 21, respectively. Yes. For this reason, when the object to be weighed X is placed on the conveyors 3ba to 3bc, the distortion generated by applying a downward load in the vertical direction on the free end 5c side of the load cell 5 is detected and converted into an electric signal, Weighing is performed based on this electrical signal.

  As shown in FIGS. 3 and 4, the AFV 6 is attached in the internal space of the frame 20 so that the longitudinal direction is along the conveyance direction A, and detects vibration from the floor surface. More specifically, as shown in FIG. 8, the AFV 6 is fixed to the fixing metal block 41, 42, 43 with screws and then fixed to the fixing block 46. In this state, after being housed inside the cover member 47, it is fixed so as to be suspended from the upper surface in the internal space of the frame 20.

As shown in FIGS. 3 and 5, the frame 20 extends in a direction orthogonal to the conveyance direction A, and stores three AFVs 6 arranged in a direction orthogonal to the conveyance direction A in the internal space. Yes.
The mounting structure of the weighing mechanism 30 including the drive motor M2, the load cell 5, the AFV 6, and the frame 20 will be described in detail later.

[Mounting structure of weighing mechanism 30]
As described above, the weighing mechanism 30 is configured to include the conveyors 3ba to 3bc, the drive motor M2, the load cell 5 (fixed end 5b, free end 5c), the AFV 6, and the frame 20 of the second transport unit 3b.
Here, the arrangement of each member will be described with reference to FIG. 7 schematically showing each member excluding the AFV 6 and the frame 20 included in the measuring mechanism 30 and FIG. 3 described in the upper part. .

  As shown in FIGS. 4 and 7, the fixed end 5b and the free end 5c of the load cell 5 are respectively formed at the front end portion and the rear end portion in the transport direction A of the load cell 5, and are drive motors that are heavy objects. M2 is disposed adjacent to the front of the fixed end 5b in a non-contact state with respect to the fixed end 5b. The drive motor M <b> 2 is connected to the free end 5 c side via an arm member 21, a frame member (connecting portion) 22, and an arm member (connecting portion) 23. Thus, by arranging the driving motor M2, which is a heavy object, on the fixed end 5b side, the position of the center of gravity of the weighing mechanism 30 can be moved from the free end 5c side to the side closer to the fixed end 5b. As a result, since the center of gravity of the weighing mechanism 30 can be placed in the vicinity of the fixed end 5b connected to the floor surface, it is possible to avoid a decrease in measurement accuracy due to the influence of vibration from the floor surface.

  The arm members 21 and 23 and the frame member 22 are formed of a material having high thermal conductivity, like the fixed end 5b and the free end 5c. For this reason, the heat released from the drive motor M2 serving as a heat source during operation is transmitted to the free end 5c side via the directly connected arm member 23, frame member 22, and arm member 21. On the other hand, the heat released from the drive motor M2 is transmitted through air and also as radiant heat to the fixed ends 5b arranged in a non-contact state but adjacent to each other. At this time, the heat directly transmitted to the load cell 5 through the arm members 21 and 23 and the heat transmitted from the short distance through the air are different in path length through which the heat is transmitted. Therefore, the heat is transmitted to the load cell 5 uniformly.

Next, the arrangement of the entire weighing mechanism 30 including the AFV 6 and the frame 20 will be described with reference to FIGS. 2, 3, 5, and 6 described above.
As shown in FIG. 2, the frame 20 to which the load cell 5 and the AFV 6 are attached is connected to the pair of front and rear legs 10 and 11 described above. For this reason, the AFV 6 attached to the internal space of the frame 20 can effectively detect vibration from the floor surface via the legs 10 and 11. And the load cell 5 is being fixed to the upper part of the flame | frame 20, as shown in FIG. That is, the load cell 5 and the AFV 6 are respectively attached to the front and back surfaces of the upper surface of the common member (frame 20). Thereby, the vibration of the floor surface transmitted to the load cell 5 can be accurately detected by the AFV 6. As a result, highly accurate weighing can be performed by subtracting the detection result in the AFV 6 from the weight value of the load cell 5. At this time, the weighing mechanism including the load cell 5 and the AFV 6 is attached in the vicinity of the bent portion of the frame 20. Thereby, the weighing mechanism having a relatively large weight can be attached to the portion of the frame 20 having high rigidity.

  Furthermore, the attachment positions 5a and 6a of the load cell 5 and the AFV 6 with respect to the frame 20 are arranged on the same straight lines L1, L2 and L3 along the transport direction A in plan view, as shown in FIGS. In other words, when viewed from the front in the transport direction A, the load cell 5 and the AFV 6 are attached so that the attachment positions 5a and 6a with respect to the frame 20 are on the same vertical line. As a result, vibration in a direction perpendicular to the transport direction A can be detected under the same conditions in the load cell 5 and the AFV 6, so that highly accurate weighing can be performed.

[Features of weight checker 1]
(1)
As shown in FIGS. 4 and 7, the weight checker 1 of the present embodiment has fixed ends on the side connected to the floor surface at both ends of the load cell 5 for weighing the objects to be weighed X conveyed on the conveyors 3ba to 3bc. 5b and a free end 5c connected to the conveyors 3ba to 3bc on which the object X is placed are arranged. And the drive motor M2 which is a non-contact state with respect to the fixed end 5b, and is a heavy article in the position adjacent to the fixed end 5b is provided. Further, the drive motor M2 is connected to the free end 5c side using arm members 21, 23 and the like.

  Thus, the drive motor M2, which is a heavy object, and the load cell 5 (free end 5c) are arranged so as to sandwich the fixed end 5b of the load cell 5, and the drive motor M2 is connected to connecting members such as the arm members 21 and 23. By connecting to the free end 5c side, the center of gravity of the entire weighing mechanism 30 can be moved to the fixed end 5b side rather than the conventional configuration. For this reason, the center-of-gravity position of the entire weighing mechanism 30 is located at a location close to the floor surface serving as a vibration source.

As a result, even when the measurement object X is placed on the free end 5c side only by changing the arrangement of each part, the influence of the moment due to vibration from the floor surface is reduced and highly accurate measurement is performed. Can be implemented.
(2)
In the weight checker 1 of the present embodiment, the drive motor M2, which is a heavy object, serves as a heat source that releases heat during operation.

Here, the drive motor M2 is connected to the free end 5c side via connecting members such as arm members 21 and 23. On the other hand, the fixed end 5b side is arranged in the vicinity of an air layer interposed therebetween.
As a result, even when the drive motor M2 serving as the heat source is disposed in the vicinity of the load cell 5, the load cell 5 and the drive motor M2 serving as the heat source are disposed in a non-contact state, so that the heat released from the heat source Adverse effects such as heating only a part of the load cell 5 can be reduced. As a result, without adding new parts such as a heat pipe or a heat sink, a change in Young's modulus or electric resistance of the sensor strain generating body prevents a four-corner error in the load cell 5 from increasing and a reduction in measurement accuracy. be able to.

Even when temperature compensation using the load cell 5 is performed, the temperature state is uniform regardless of the sensing location. Therefore, the temperature is affected by fluctuations in the room temperature where the apparatus is installed and the heat of the drive motor M2. However, the error can be reduced and the compensation calculation can be performed more accurately.
(3)
In the weight checker 1 of the present embodiment, the fixed end 5b and the free end 5c arranged on both sides of the load cell 5, the arm members 21 and 23 as the connecting members, and the frame member 22 are formed of a material having high thermal conductivity. .

  Here, although the fixed end 5b disposed at a position adjacent to the drive motor M2 serving as a heat source is disposed at a short distance but is not in direct contact with the drive motor M2, heat is transmitted via air. The On the other hand, although the free end 5c is arranged at a farther distance than the fixed end 5b, heat is directly transmitted through the arm members 21, 23 and the like formed of aluminum alloy having a high thermal conductivity. .

  Thereby, since each member can be used as an adjustment mechanism for adjusting the heat transfer to the load cell 5, heat can be uniformly transferred to the fixed end 5b side and the free end 5c side with respect to the load cell 5. . For this reason, the temperature gradient in the load cell 5 can be made substantially uniform, so-called four-corner errors in the load cell 5 can be reduced, and more accurate weighing can be performed.

Further, by using a material having high thermal conductivity for the fixed end 5b, the free end 5c, the arm members 21, 23, etc., the time required to reach the thermal equilibrium state in the entire apparatus is shortened, so the rise time is shortened. be able to.
(4)
In the weight checker 1 of the present embodiment, as shown in FIGS. 3 and 7, a fixed end 5 b as a windbreak wall is disposed between the drive motor M <b> 2 and the load cell 5, which are heavy objects.

Thereby, even when an air flow occurs in the drive motor M2, it is possible to prevent the air flow from affecting the weighing in the load cell 5. As a result, more accurate weighing can be performed.
(5)
In the weight checker 1 of the present embodiment, the heavy drive motor M2 and the load cell 5 are housed in the same housing 7.

Thereby, while being able to prevent the dust, dust, moisture, etc. from the outside, the measuring device excellent in cleanability can be obtained.
(6)
In the weight checker 1 of the present embodiment, a drive motor M2 that rotationally drives the conveyor belts of the conveyors 3ba to 3bc is mounted as a heavy object.

As a result, even when the drive motor M2 functions as a heavy object and a heat source, it is possible to reduce the influence of vibration from the floor and the influence of heat released from the drive motor M2, and to perform highly accurate weighing. A possible metering device can be obtained.
[Other Embodiments]
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.

(A)
In the said embodiment, the drive motor M2 was mentioned as an example and demonstrated as a heavy article contained in a weighing | measuring apparatus. However, the present invention is not limited to this.
For example, in addition to the drive motor, a cylinder, a weighing hopper (see FIG. 9), a weighing pan, or the like that rotates a part of the transport conveyor in the vertical direction to distribute the objects to be weighed may be used. Even in this case, since the free end of the weighing sensor and the heavy object are respectively arranged on both sides around the fixed end of the weighing sensor (load cell), the position of the center of gravity of the weighing device is located on the side where the heavy object is arranged. Can be moved. As a result, the center of gravity of the device is moved from the free end side to the fixed end side in contact with the floor, and the weighing accuracy of the weighing sensor is affected by the vibration on the floor. It is possible to obtain the same effect as described above that it is possible to carry out weighing with higher accuracy than in the past.

Moreover, in the said embodiment, drive motor M2 was mentioned as an example and demonstrated as a heavy article used as a heat source. However, the present invention is not limited to this.
For example, the above-described cylinder or the like can be used as a heavy object serving as a heat source. Even in this case, by accurately transferring heat to the load cell, it is possible to reduce the four-corner error in the load cell and perform highly accurate weighing.

(B)
In the said embodiment, the example using the load cell 5 was given and demonstrated as a measurement sensor. However, the present invention is not limited to this.
For example, force balance may be used as a weighing sensor instead of a load cell.
In this case, by detecting the current value generated by the differential transformer in the force balance that occurs when the object to be weighed is placed on the weighing position, the force balance characteristic allows the load cell to be used as a weighing sensor. Further, highly accurate weighing can be performed.

(C)
In the above embodiment, as shown in FIGS. 4 and 7, etc., the drive motor M2, the fixed end 5b, the load cell 5, the free end 5c, the arm members 21, 23 and the like have been described as examples. However, the present invention is not limited to this.
For example, as shown in FIG. 9, the load cell 55, its fixed end 55b, the free end 55c, and the heavy article M53 may be arranged in the vertical direction. In this case, the fixed end 55 b side is fixed to the wall 60, and the weighing hopper 52 and the heavy object M 53 are attached via the connecting member 51, so that the center of gravity of the apparatus is fixed to the fixed end 55 b connected to the wall 60. By moving to the side, it is possible to obtain the same effect as described above that the weighing object stored in the weighing hopper 52 can be measured with high accuracy.

(D)
In the above embodiment, as shown in FIGS. 4 and 7, etc., an example in which the drive motor M2, the fixed end 5b, the load cell 5, the free end 5c, the arm members 21, 23, and the like are arranged in the horizontal direction when viewed from the side. explained. However, the present invention is not limited to this.
For example, the members may be arranged so that the members are aligned in the horizontal direction when viewed from the front. In this case, since the length in the conveyance direction of the conveyor can be made shorter than the conveyors 3ba to 3bc of the above embodiment, it is possible to cope with the downsizing of the conveyor.

(E)
In the above embodiment, as an adjustment mechanism for adjusting the amount of heat transmitted to the load cell (metering sensor) 5, the arm members 21 and 23 and the frame member 22 formed of a material having high thermal conductivity, the fixed end 5b. An example using the free end 5c has been described. However, the present invention is not limited to this.

  For example, the arm members 21 and 23, the frame member 22, the fixed end 5b, and the free end 5c may be formed of a material having a low thermal conductivity, and these may be used as the adjusting mechanism. Even in this case, the heat released from the drive motor as a heat source is blocked by the fixed end 5b, and the heat transmitted to the load cell 5 through the arm members 21, 23, etc. is hardly transmitted. Thus, highly accurate weighing can be performed.

  Further, as an adjustment mechanism for adjusting the amount of heat transmitted to the load cell (metering sensor) 5, a member such as a heat insulating material or a heat radiating plate attached to the surface of the fixed end 5b on the heat source side may be used. Furthermore, an adjustment mechanism may be provided by arranging the drive motor M2 such that the portion of the drive motor M2 that releases heat is away from the fixed end 5b. In any of these cases, it is possible to reduce the four-corner error in the load cell and perform highly accurate weighing.

(F)
In the above embodiment, the fixed end 5b and the free end 5c disposed on both sides of the load cell 5, the arm members 21, 23 as the connecting members, and the frame member 22 are formed of a material having high thermal conductivity such as an aluminum alloy. And explained. However, the present invention is not limited to this.

For example, each member may be formed using a material partially having high thermal conductivity for the connecting portions. Even in this case, heat from the heat source can be uniformly transmitted to the weighing sensor such as the load cell on the fixed end side and the free end side, so that the so-called four-corner error can be reduced and highly accurate weighing can be performed. It becomes possible.
Further, as a material having a high thermal conductivity, other metals having a high thermal conductivity such as stainless steel and copper may be used in addition to the aluminum alloy.

(G)
In the above embodiment, an example in which the present invention is applied to the weight checker 1 has been described. However, the present invention is not limited to this.
For example, in addition to the weight checker, the present invention can be applied to a weighing device that performs weighing by mounting a weighing hopper, various weighing sensors, and the like. Even in this case, it is possible to obtain a weighing device capable of reducing the adverse effects due to vibration from the floor surface and heat from the heat source and always performing highly accurate weighing.

  The weighing device of the present invention has the effect of reducing the influence of vibration on the floor surface and performing highly accurate weighing. Therefore, the weighing device is suitable for various weighing devices equipped with weighing sensors such as load cells and force balance. And widely applicable.

The front view which shows the external appearance of the weight checker which concerns on one Embodiment of this invention. The top view which shows the weight checker of FIG. FIG. 2 is an enlarged view showing a structure around a weighing mechanism included in the weight checker of FIG. 1. The figure which expanded further the part of the measurement mechanism of FIG. The top view which shows the attachment position of the measurement mechanism of FIG. The figure which looked at the measurement mechanism of FIG. 4 from the conveyance direction. The figure which showed typically the attachment structure of the measurement mechanism of FIG. The perspective view which shows the hanging attachment structure of the load cell contained in the measurement mechanism of FIG. The schematic diagram which shows arrangement | positioning of each member contained in the weighing | measuring apparatus which concerns on other embodiment of this invention.

Explanation of symbols

1 Weight checker (weighing device)
DESCRIPTION OF SYMBOLS 3 Conveyor apparatus 3a 1st conveyance part 3b 2nd conveyance part 3c 3rd conveyance part 3aa-3ac Conveyor 3ba-3bc Conveyor 3ca-3cc Conveyor 5 Load cell (measurement sensor, 1st measurement sensor)
5a Mounting position 5b Fixed end (adjustment mechanism, windbreak wall)
5c Free end 6 AFV (load cell, second weighing sensor)
6a Mounting position 7 Case 10, 11 Leg 13 Roller (drive roller)
15 Roller (driven roller)
20 frame (support member)
21 Arm member (connecting part)
22 Frame member (connection part)
23 Arm member (connecting part)
30 Weighing mechanism 52 Weighing hopper 55 Load cell (weighing sensor)
55b Fixed end 55c Free end 60 Wall M1 Drive motor M2 Drive motor (heavy object, heat source)
M53 Heavy item X Item to be weighed

Claims (8)

A weighing sensor for weighing an object to be weighed;
A fixed end to which the weighing sensor is attached;
An end of the weighing sensor opposite to the fixed end, and a free end on which the object to be weighed is placed;
A heavy object placed in a non-contact state with the fixed end at a position such that the fixed end is sandwiched between the weighing sensor,
A connecting portion for connecting the free end and the heavy object;
Weighing device equipped with. The heavy object is a member that releases heat.
The weighing device according to claim 1. An adjustment mechanism for adjusting the amount of heat released from the heavy object and transferred to the weighing sensor;
The weighing device according to claim 2. The fixed end and the connecting portion are formed of a material having high thermal conductivity.
The weighing device according to claim 3. The fixed end and the connecting portion are formed of a material having low thermal conductivity.
The weighing device according to claim 3. The fixed end has a wind barrier that blocks a flow of air generated by the movement of the heavy object and flowing toward the weighing sensor.
The weighing device according to any one of claims 1 to 5. The heavy object and the weighing sensor are housed in the same housing.
The weighing device according to any one of claims 1 to 6. A transport conveyor for transporting the object to be weighed in a predetermined direction;
The heavy object is a drive motor that drives the conveyor.
The weighing device according to any one of claims 1 to 7.

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